DICOM Correction Item
Correction Number: CP-155
Submission Abstract: Add support for ISO-IR 149 Korean character sets
Type of Change Proposal:
Name of Document:
Addition
PS 3.3-1999: Information Object Definitions,
PS 3.5-1999: Data Structures and Encoding
Rationale for change:
Korea uses its own characters, Hangul, and Hangul needs to be used in DICOM. Hangul can be
implemented easily in DICOM by character encoding methods that PS 3.5 has defined. A Defined Term
for Character set for Hangul needs to be added in Table C.12-4 of PS 3.3
Sections of document affected/ Suggest Wording of Change:
Part 3
1. C.12.1.1.2 Specific Character Set
Add the following entry to Table C.12-4.
Table C.12-4
DEFINED TERMS FOR MULTIPLE-BYTE CHARACTER SETS WITH CODE EXTENSIONS
Character Set Defined
Standard
ESC
ISO
Number of
Code
Character
Description
Term
for Code
Sequence registration characters element
Set
Extension
number
Korean
ISO 2022 ISO 2022
ESC 02/04 ISO-IR 149
942
G1
KS X 1001:
IR 149
02/09 04/03
Hangul and
Hanja
Part 5
1. Section 2
Add the following Hangul multi-byte character set to the end of section 2 “Normative references”:
KS X 1001-1997
Code for Information Interchange (Hangul and Hanja)
2. Section 6.1.2.4 Code Extension Techniques
Modify the Note to read:
2. Support for Japanese kanji (ideographic), hiragana (phonetic), and katakana(phonetic)
characters, and Korean characters (Hangul) is defined in PS3.3. Definition of Chinese
Korean, and other multi-byte character sets awaits consideration by the appropriate standards
organizations.
3. Change the current Annex I to Annex J and add the followings as Annex I, “Character sets and person name
value representation in the Korean language”.
Annex I
(Informative)
Character sets and person name value representation In the Korean Language
I.1 CHARACTER SETS FOR THE KOREAN LANGUAGE IN DICOM
KS X 1001 (registered as ISO-IR 149) is used as a Korean character set in DICOM. This
character set is the one most broadly used for the representation of Korean characters. It can
be encoded by ISO 2022 code extension techniques, and is registered in ISO 2375.
Escape Sequence (for reference) (see PS 3.3)
G0 set
G1 set
Notes:
ISO-IR 149
ESC 02/04 02/08 04/03
ESC 02/04 02/09 04/03
1. ISO-IR 149 is only used as a G1 set in DICOM.
2. The Korean character set (ISO IR 149) is invoked to the G1 area. This is different from the
Japanese multi-byte character sets (ISO 2022 IR 87 and ISO 2022 IR 159) which use the G0
code area. Japan's choice of G0 is due to the adoption of an encoding method based on
"ISO-2022-JP". ISO-2022-JP, the most familiar encoding method in Japan, and uses only
the G0 code area. In Korea, most operating systems adopt an encoding method that invokes
the Hangul character set (KS X 1001) in the G1 code area. So, the difference between code
areas of Korean and Japanese character originates in convention, not a technical problem.
Invocation of multi-byte character sets to the G1 area does not change the current DICOM
normative requirements.
I.2 EXAMPLE OF PERSON NAME VALUE REPRESENTATION IN THE KOREAN
LANGUAGE
Person names in the Korean language may be written in Hangul (phonetic characters), Hanja
(ideographic characters), or English (single-byte characters). The three component groups
should be written in the order of single-byte, ideographic, and phonetic (see Table 6.2-1).
(0008,0005) \ISO 2022 IR 149
Character String:
Encoded representation:
04/08 06/15 06/14 06/07 05/14 04/07 06/09 06/12 06/04 06/15 06/14 06/07 03/13
01/11 02/04 02/09 04/03 15/11 15/03 05/14 01/11 02/04 02/09 04/03 13/01 12/14
13/04 13/07 03/13 01/11 02/04 02/09 04/03 12/08 10/11 05/14 01/11 02/04 02/09
04/03 11/01 14/06 11/05 11/15
Result of representation by an ASCII-based machine which displays 01/11 as \033:
Hong^Gildong=\033$)C\373\363^\033$)C\321\316\324\327=\033$)C\310\253^\033$)C\261\3
46\265\277
Notes: 1. The multi-byte character set (ISO-IR 149) and single-byte character set (ISO 646)
can be used intermixed without any explicit escape sequence after the initial escape
sequence. Once ISO 646 has been designated to the GL area and ISO-IR 149 to the
GR area, each character set has different code area, thus can be used intermixed.
The decoder will check the most significant bit of a character to know whether it is a
two byte character in the GR area (high bit one) or a one byte character in the GL
area (high bit zero).
2. In the above example of person name representation, explicit escape sequences
precede each Hangul and Hanja string. These escape sequences are to meet the
requirements of the code extension technique that specifies a switch to the default
character repertoire before delimiters. In the previous example, it is assumed that the
default character repertoire (ISO-646) is invoked to G0 code area and no character
set to G1 area after delimiters (“^” and “=” signs). See 6.1.2.5.3 of PS 3.5.
I.3 EXAMPLE OF LONG TEXT VALUE REPRESENTATION IN THE KOREAN LANGUAGE
WITHOUT EXPLICIT ESCAPE SEQUENCES BETWEEN CHARACTER SETS
Hangul (ISO IR 149) and ASCII (ISO 646) character sets can be used intermingled without
explicit escape sequences between them. The Hangul character set ISO IR 149 is invoked to
the G1 area, so this invocation doesn't affect the G0 area to which the ASCII character set has
been invoked. The following is an example of a Long Text value representation which includes
ASCII and Hangul character set.
(0008,0005) \ISO 2022 IR 149
Once having invoked the ISO IR 149 character set to G1 area by the escape sequence in the
head of line, one can use Hangul and ASCII intermixed in that line.
Table I-1.
CHARACTER SETS AND ESCAPE SEQUENCES USED IN THE EXAMPLES
Character
Set
Description
Korean
Component
Group
First:
Single-byte
Second:
Ideographic
Third:
Phonetic
Value of
(0008,0005)
Defined
Term
Value 1:
none
Value 1:
none
ISO
Registration
Number
ISO-IR 6
Value 2:
ISO 2022 IR
149
ISO-IR
149
Value 1:
none
ISO-IR 6
Value 2:
ISO 2022 IR
149
ISO-IR
149
Standard
for Code
Extension
ESC
Sequence
GL
ISO-IR 6
GL
ISO 2022
ESC 02/04
02/09
04/03
GR
GL
ISO 2022
ESC 02/04
02/09
04/03
GR
Character
Set:
Purpose of
Use
ISO 646:
ISO 646:
For
delimiters
KS X 1001:
Hangul and
Hanja
ISO 646:
For
delimiters
KS X 1001:
Hangul and
Hanja